Air-pump



\ I. LAWLEYf- AIR PUMP.

APPLICATION FILED OCT. 28, 1919.

Patented Oct. 19,1920.

Z /5/ v v, I '7 '2 5] n newton [2% Ian 12y units!) STATES IRA LAWLEY, OF GROESBECK, TEXAS.

PATENT OFFICE.

AIR-PUMP.

nsseaeo.

To (all ie/ mm it may concern:

Be it known that 1, TBA LAWLEY, a citizen of the United States, residing at Groesbeck, in the county of Limestone and State of Texas, have. invented certain new and useful Improvements in Air-Pumps, of which the following is a specification.

This invention relates to new and useful improvements in air pumps.

The object of the invention is to provide a tire pump thatwill expel substantially all of the air from the cylinder at each opera tion of the plunger and one that will obviate the pumping of lubricating oil from the cylinder of the pump into the air passages leading from the pump to the tire and thence into the tire, thus permitting the pump to be maintained well lubricated; and also a compact pump provided with a sheath for the air exhaust tube and means for securing the sheath to the pump to preclude the loss of the sheath.

In carrying out the invention. I use a pump having a cylinder in which a plunger operates, said plunger having an air; passage extending through the same and a check valve in the air passage to preclude the return of the air from the pumping chamber through the passage on the downwardstroke of the plunger, but admitting an ample supply of air to the pumping chamber on the upward stroke of the plunger, thus permitting a heavy packing to be used between the plunger and the inner surface of the cylinder. The plunger being so shaped as to seat snugly into the bottom of the cylinder and a heavy packing between the plunger and the inner surface of the cylinder causes a minimum amount of air to be left in the pumping chamber at each operation of the plunger. v

A check valve precludes the return of compressed air from the exhaust tube into the cylinder on the upward stroke of the plunger.

A plug fixed in the bottom of the cylinder and having a central passage with radial parts leading from the top of the passage and an absorbent wick disposed with n the central passage precludes the dripping of lubricating oil from the plunger into the air passage and the pumping of the oil thence into the tire, thus permitting the pump to be maintained well lubricated.

A very important feature of the invention is a sheath for protecting the exhaust tube Specification of Letters Patent. Patent d Oct 19 1920 Application filedOctober 28, 1919. Serial .No. 333,998. I

when the pump is not in operation, the said sheath being secured to the pump when the latter is in operation to preclude the loss of the sheath. I i A The invention will be more readily understood from a reading of the following specilication and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a side elevation ofa tire pump constructed in accordance with this invention, 1 Fig. 2 is a detail view of the top of the pump, showing the bayonet joint locked,

Fig. 3 is a partial elevation showing the sheath secured to the pump when the air tube is removed from the sheath,

F ig.4 is a detail of the bayonet joint,

Fig. 5 is a plan view in sectionof thebase of the pump, and Y 7 s Fig. 6 is a sectional view on the line 33 of Fig. 5. A

In the drawings the numeral 10 designates a vertical pump cylinder resting in a countersink 11 in the base l2 of an air-pump and secured therein, the said cylinder having I a top 18 with an intake opening14 in the same for supplying air to the cylinder.

A plunger 15 having an upwardly extending shank 16 protruding through an aperture 17 in the top 13 is disposed within the cylinder in such a manner as to be vertically operated by means of a handle member 18 surmountingthe shank. An intake air passage 19 extending through the plungeradniits the air to that portion of the-cylinder below the plunger at each upward strokeJof the latter, the air being retained therein by means of a valve 20 retained adjacent the centerof the plunger by a perforate retaining member 21 at the downward stroke of the plunger, the compressed air in the cylinder acting to move the said valve into en gagement with the underside of the plunger at each downward stroke of the plunger so as to close the said intake passage whereas at each upward strokeof the plunger the said valve is .released and rests in the per- 7 A coil spring 23 surrounding the shank 16 assumes the relation of a cushion between the plunger 15 and the top 13 when the said plunger is in operation.

A plug 24 removably fixed centrally .ot' the base, within the cylinder so as to project above the said base, and having a central passage 25 and radial ports 26 leading from the top of the central passage precludes the dripping of lubricating oil from the plunger into the air discharge passage and the pumping of said lubricating oil thence into the tire, an absorbent wick being so disposed within the central passage as to filter the discharged air and remove all oil therefrom. Thus the pump may be maintained well lubricated without the lubricant getting into the tire and causing damage to the latter.

The plunger being shaped to seat snugly into the bottom of the cylinder, a minimum amount of compressed air remains within the cylinder at each operation of the plunger. A check valve 27 in the air discharge passage 28 precludes the return of compressed air from the flexible discharge tube 29 into the cylinder. By a minimum amount of compressed air remaining within the cylinder after each operation of the plunger and the return of compressed air from the discharge air tube precluded, a maximum of efliciency is obtained in the operation of the pump.

The pump is supported in a vertically disposed position while in operation by means of a foot pressed supporting member 30 iv otally connected with the base and frictionally retained in engagement with the surface upon which the base of the pump rests by transversely disposed bosses 31 projecting laterally from the base, the said supporting member being foldable close to the cylinder when not in use and frictionally retained in the said folded position by means of the said bosses.

The flexible air discharge tube 29 is protected by a sheath 32 disposed parallel of the cylinder when the plunger is not in operation, the lower end of the said sheath engaging a vertically disposed boss 33 intewith the base 12, the said boss having a socket 34 centrally of the upper surface of the same for receiving and retaining the said air discharge tube by means of a nipple 35, and the upper end of the sheath engaging in a bayonet joint 36 integral with the top 13, the said bayonet joint being locked or unlocked by means of a pin 38 extending laterally from the sheath and engaging in an angular slot 39 in the bayonet joint by a circumferential movement of the sheath. Upon withdrawing the tube from the sheath for putting the pump into opera tion the sheath is removed from engagement with the boss 33 and moved into engagement with a second vertically disposed boss 37 integral with the base 12, thus obviating the loss of the sheath. This is a very important feature of the invention.

It is noted that the construction embodied in a pump of the nature described provides a compact, durable and eflicient air pump and one that can be manufactured at a moderate cost.

What I claim, is:

1. In a tire pump, the combination of, a base provided with a plurality of upstanding bosses, a pump cylinder connected with the base and extending upwardly with relation thereto, a plunger to reciprocate within the pump cylinder, means to move the plunger, a flexible air tube attached to one boss, a sheath tube adapted to removably receive the flexible air tube and to detachably receive either boss, and a ring secured to the upper portion of the pump cylinder and receiving the upper end of the sheath tube.

2. In a tire pump, thecombination of, a base provided with a plurality of upstanding bosses, a pump cylinder connected with the base and extending upwardly with relation thereto, a plunger to reciprocate within the pump' cylinder, means to move the plunger, a flexible air tube attached to one IRA LZUVLE Y. 

